Method of producing a fibrous mass impregnated with a phenolic condensation product



Oct. 20, 19 5 1557,730

F 5. SMITH METHOD OF PRODUCING A FIBROUS MASS IMPREGNATED WITH A PHENOLIC CONDENSATION PRODUCT Filed Feb. 15, 1921 INVENTOR JAM ATTORNEY.

Passed a. 20, 19225 FRANKLIN s. scm'rn, or PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TOTHE PROD:

"" S O E Q 9 0 3 11 OF NEW YORK, N. Y., A OOBIORATION'WF DELAWARE.

nmon or rnonucnve armnous mrnEeNATEn win: a rHENoIQic DENSATION PRODUCT.

Application filed Ma 15, 1921. Serial No. 445,114.

To all whom it may concern:

Be-it'known that I, FRANKLIN S. SMITH, a citizen of the United States, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented an Improvement in the Meth- 0d of Producing a Fibrous Mass Impregnated with a Phenolic Condensation Product, of which the following is a specification.

pro ucing. material consisting of organic eitherv in the intermediate or B form, in

fibers such as jute, cotton, etc., impregnated with a phenolic condensation product, for

instance, bakelite; the said product being Y which itis moldable, or in'the final or form. I

. One of the objects of my invention is to provide a novel method whereby an improved material consisting of organic uncut or natural fibers impregnated with an intermediate phenolic condensation product, as bakelite B, the said fibers so impregnated being moldable may be .produced.

A still further object of the invention is toprovide an improved and novel method whereby a material may be produced which in its final condition, in which'the con-- densation product has been converted into the solid G form, possesses among other I characteristics .those of high tensile and dielectric strength (the latter being uniform in all directions), toughness and requisite homogeneity.

Another object ofthe invention is to provide a ractical and workable method for the pro notion of material of the character above mentioned. I

Still another object of the invention is to detailed description thereof which follows or will be apparent fr m such description. In the carrying on of my invention I take the spun fibers of jute (which I have 'current of a voltage such as will .proda ea found to be especially well adapted toiithe purposes of my invention), cotton pr fotherv l1ke or equivalent materials, andfimpreg nate them with an, initial condensation product, such as bakelite A. on ay of effecting this is to take the fibers-lathe form of yarn (by' which term I str1ng,' thread, cord, twine, et'c.,) w'h been wound into balls, and placethe,

in a suitable receptacle containing tial phenolic condensation product,'; as' bake;

lite A in solution in a mixture of ethylfori alcohol and benzol intpro oynens which may range from thirty to'se'venty p r; cent. of alcohol by volume and from seventy per cent. of benzol to 'efieot im-f pregnation thereof. In practice the'jjfiber balls of yarn are placed in astron g'meff ceptacle WlllCh is then hermetically sealed; and the solution of bakelite Asupplied methyl to thirty such receptacle under a pressure of] ap'-:

proximately ten thousand pound'sl'lpe'r square inch. The yarn is found -to"b e or sufiiclently impregnated within affperioc lii of a 'few minutes, five to ten, 'altho'ughfthe fiber balls of am may be allowejdfto re? main in the so ution for a longer period j i f desired. Such longer or additional tre a't-Q,v ment does not appear to have any"beneficialj effect; neither-does it appear to jha'vje'f deleterious or injurious eflect. If'the sure is decreased the timeflrequired j fect complete impregnation is incr ij edandffby leaving the balls of fiber in ,the s0 1u-;1

-tion for a sufficient length of timef say' a;

few days, impregnation may b s acreage The halls of yarn are then removed from the solution..and'the atmospheric pressure.

solvent removed therefrom. To efi'ectfrapid and efficient removal of the solvent not only, g

from the surface but from the interior the impregnated yarn or string i mi n unwound from the saidball ;.;a1r1e1,; drum or the like, or a ball, and asfitpa'ssesjj;

from the first named ball to the'flatte'r orjj:

to a reel'or drum it is subjected to' e voltage gradient at the surfacefof or string sufiicient to form boron v j The gradient necessary-to form jco'ron 31.5 Kv./Cm. at standard temperaturej'and barometric pressure. The first namedball from which the yarn is unwound is lnsulated and the arn which is unwound therefrom is asse or moved in contact withan insulate metal terminal of suitable form having connection with one end of the secondary of a transformer the other end of which is grounded. Specifically, as illustrated in the drawing in which Fig. 1 is a view partly insection and partly in side elevation of a portion of apparatus which may be employed in the carrying out of the invention and Fig. 2 a transverse sectional view taken on the line 2-2 of Fig. 1, a plurality of metal rings 1 (of large diameter as compared with the yarn or string) are secured upon a metal bar 2 which is in-' sulated and which is connected to one end of the secondary 2 of a transformer, the primary of which is shown at 4. The opposite side or end of the secondary is grounded, as indicated at 6, and is connected to a rod or wire 7 which extends through the said rings and is concentric therewith. The said rod or wire 7 is supported by any suitable support of insulatmg material, not shown. The yarn 8 is drawn through these rings in contact with any point thereof and corona is produced thereon as indicated by the divergent lines at 9. The charging of the yarn and the producing or formlng of corona thereon causes the yarn or string to vibrate very rapidly and effects removal of the solvent therefrom. The yarn, before reaching the rings (or other form of contacts) is conducting but after leaving the same is nonconductmg, it having been freed of the solvents. The rings or other suitable contacts are spaced short distances from each other, and by varying the number thereof the s eed at which the yarn can be unwoun from the' first .named reel may be varied. By increasing the number so that the yarn is kept in contact with the contact members for a longer period as it travels along, the speed of movement thereof may be increased. While it is possible to convert the phenolic condensation product from the A to the B form by the action of the electric current such practice is not followed because of the time which would be required. In order, therefore, to convert the said product from the A to the B form the impregnated yarn, after the last mentioned step of the treatment, is heated to a temperature of from to centlgrade,

which effects conversion to the intermediate or B stage. A much higher temperature may be employed but its use requires much greater skill and experience.

The yarn or string thus treated and when cold is hard and wiry, but upon being heated to about eighty degrees; centigrade and above becomes soft and pliable and may be molded into any shape desired.

In employing the material consisting of yarn of organics un fiber im re ated with bakelite B f r the manuf ct i' e of articles of whatever kind may be desired, and for which the said material may be suitable, an amount of the said yarn sufficient for the purpose in hand is. packed into molds, previously heated. The mold is of a temperature above eighty degrees centigrade, preferably around one hundred and thirty degrees. The material when packed into the molds thus heated very quickly becomes soft and liable, whereupon the plunger or die of a press into which the mold has previously been placed is moved down into the mold and the said material is subjected to pressure to form it into the shape of the mold which may be of the shape required for the purpose in hand. The pressure employed may range from one thousand tofive thousand pounds per square inch. The pressure and the temperature are maintained for a period of time, depending upon the thickness of the article being molded or formed, during which the bakelite B is converted into bakelite C.

The impregnated yarn is packed indiscriminately that is, in a tangled or haphazard condition, into the mold so that one portion. of yarn may be and is interlocked.

with another portion, the fibers thereof being thus interlocked and bound together.

The term bakelite employed in'the specification and claims is used in a descriptive and not in a limiting sense and is intended to comprehend phenolic condensation products suitable. for the purpose herein described and which possess or have the characteristics above indicated.

Having thus described my invention, what I claim and desire to secure by Letters Patent, is:

1. The method of producing a string of 'organic material impregnated with an intermediate phenolic condensation product which comprises first, impregnating the same with an initial phenolic condensation product in solution and thereafter charging the same with an electric current of high tension and producing corona thereon.

2. The method of producing a string of organic material impregnated with bakelite B, which comprises first impregnatingthe same with bakelite A in solution, thereafter charging the same with an electric current of high tension and producing corona thereon, and simultaneously moving the string forward past and in contact with the charging means.

3. The method of producing a string of organic material impregnated with bakelite B, which comprises the dissolving of bakelite A in a suitable solvent, thereafter impregnating the said string with the solution thus formed, subjecting the same to the accharge upon the said string to remove the solvent therefrom and converting the to an intermediate phenolic condensation product.

' comprises impregnating organic fiber with a solution of bakelite A, thereafter subjecting the said fiber to an electric charge of high tension and producing corona thereon to remove the solvent, thereafter applying heat to convert the bakelite A into bakehte-B, and thereafter lacing the saidimpregnated fiber in a mol vand simultaneously subjecting it to pressure and heat at a temperature above eighty degrees centigrade.

6. The method of producing a solid fibrous mass of the character described comprising the impregnatin of a string of organic fibers with bake 'te A in solution,

thereafter charging the said string with an electric current of high tension and producing corona thereon and simultaneously removing the solvent therefrom and also simultaneously movin the strin forward, converting the bakehte A into akelite B and thereafter packing the said string into a mold and subsequently 7 simultaneously subjecting it to pressure and heat at a temperature above eighty degrees centigrade, substantially as described.

7. The method of producing a fibrous solid mass of the character described, comprising dissolving bakelite A in a mixture of alcohol and benzol, placing organic fiber string within the solution thus formed under pres sure, thereafter removing the said string from the said solution and charging the same with an electric current of hightension to efiect removal of the solvent, converting the bakelite A into bakelite B, the said string being thereafter packed into a moldand subsequently simultaneously subjected to the action of pressure and heat at a temperature above ei hty de centi d'e.

In testimony at 1' im the oregoing as my invention, I have hereunto subscribed 7 my name this 7th day of February, A. D. 1921.

7 VS. SMITH. 

